IMMUNOCHEMICAL AND IMMUNOHISTOCHEMICAL CHARACTERIZATION OF A SYNAPTICMEMBRANE-PROTEIN THAT BINDS THE COMPETITIVE ANTAGONISTS OF NMDA RECEPTORS

An approximately 54-kDa protein that has binding sites for the competi tive N-methyl-D-aspartate (NMDA) receptor antagonists +/-)-2-carboxypi perazine-4-yl)-propyl-1-phosphonic acid (CPP) and (+/-)-(E)-2-amino-4- propyl-5-phosphonopentenoic acid (CGP 39653) was purified from rat bra in synaptic membranes. Polyclonal antibodies to this protein reacted s pecifically with an approximately 54-kDa protein in synaptic membranes and immunoextracted approximately 60% of [H-3]CGP 39653 binding sites associated with solubilized membrane proteins. The antibodies also la beled antigenic sites in the perikaryon and apical and basilar dendrit es of pyramidal neurons of the hippocampus and cerebral cortex.